The Germany international will miss the rest of the season for BVB as he undergoes treatment for "metabolic disorders".

Gotze returned to Signal Iduna Park from Bundesliga rivals Bayern Munich at the start of this season, but the Germany international has struggled for form this term.

However, Watzke is adamant that the World Cup winner will play a key role for Dortmund for years to come.

"We have very high hopes that he will fully recover and get back to his best," Watzke told Sport Bild.

"If the treatment is successful, and things appear to be going well right now, Mario can rediscover his best form eventually.

"He is doing alright if you bear the circumstances in mind. But it is only logical that an ambitious professional like Mario is not feeling great when you are missing the decisive stages of the season and big games against Bayern.